Logging truck swept off road by landslide
Date of incident: November 2015
Notice of incident number: 2015162930073
Employers: Log-hauling company; timber-harvesting company; timber tenure-management company; geological consulting company
On a cutblock access road on the side of a mountain, a driver was moving a loaded logging truck away from the loading point to put on binders. A landslide came down the slope and swept the logging truck off the road and down the mountainside. The truck driver sustained fatal injuries.
- Worker and logging truck swept down steep slope by landslide. On an old, unmaintained logging road 600 metres above the work zone, heavy precipitation and snowmelt initiated a landslide. The landslide swept down the mountainside through an active cutblock and carried the loaded logging truck and its driver downslope approximately 300 metres, burying the truck in debris.
- Abandoned logging road was not assessed. The tenure-management company commissioned a terrain stability assessment prior to the start of the logging operations. The geological consulting firm that conducted the assessment did not examine the abandoned logging road upslope of the cutblock. The road constituted an upslope hazard of landslide, which was not addressed in subsequent logging plans for the cutblock.
- Abandoned logging road was not deactivated. The abandoned logging road was on Crown land. The road had not been deactivated after it was no longer being used for logging activities because, according to the Ministry of Forests, Lands, Natural Resource Operations and Rural Development, it did not meet the criteria for deactivation. Deactivation of the abandoned logging road would have reduced or eliminated the risk of landslides.
- Rainfall shutdown guidelines were not properly applied. The rainfall shutdown guidelines in the site plan provided to the logging crew by the tenure-management company did not contain any reference to the effects of snowmelt on cumulative soil saturation. The guidelines in the site plan were taken from the terrain stability assessment, which advised that crews should be aware that periods of extreme precipitation and snowmelt could cause instability on slopes even prior to reaching the shutdown criteria. This advice was not included in the site plan.
- Risk of landslide was not recognized. The process for collecting rainfall and the interpretation of the data collected were inadequate. The measurements were not taken at regular times, the time of collection was not recorded, and ongoing rain accumulation throughout the shift was not accounted for. Evidence indicates that the shutdown guidelines had been exceeded sometime during the shift.
The timber-harvesting firm decided the logging crew would work that day, even though rainfall amounts were within 8 millimetres of the shutdown measure given in the site plan. This decision was made despite the fact that it was raining and that snow was visible on the slope above the work area.The implications of the increased risk of landslide caused by the amount of soil saturation from melting snow were not understood. Snowmelt was not considered in addition to the precipitation measured.